This invention relates to a gamma radiation resistant carbonate polymer composition wherein the polycarbonate polymer is rendered radiation resistant by the incorporation of an effective amount of one or more linolenic compounds.
There is a distinct need for polycarbonate moldings that are resistant to gamma radiation so that they can be sterilized without substantial loss of clarity and physical characteristics.
It is known that polyolefins can be rendered radiation resistant by the addition of benzhydrol, hydrocarbon oils, phthalic esters, and benzaldehyde acetals. See for example U.S. Pat. Nos. 4,431,497, 4,460,445; and 4,467,065.
It is also known that blends of polycarbonate resins and polyethylene terephthalate are resistant to gamma rays. Modern Plastics January 1984 page 104: Plastics World December 1983 pages 68 and 69.
The use of various stabilizer compounds such as esters, alcohols, thioesters, thiadiazoles, thiourea, phosphonates, phosphonites, and diphosphonites is disclosed in EP-0152,012.